Method and apparatus for treating fibrous containers



Feb. 16, 1943.

H. A. BERGSTROQ/i METHOD AND APPARATUS FOR TREATING FIBROUS CONTAINERS Filed Oct. 22, 1940 3 Sheets-Sheet l WINK hbbbbbbbbbbbujhbbdbb INVENTOR Harold A. Bergsrrom.

ATTORNEYS Feb. 16, 1943. BERGSTRQM 2,311,309

MBTHOD AND APPARATUS FOR TREATING FIBROUS CONTAINERS Filed Oct. 22, 1940 3 Sheets-Sheet 2 INVENTOR ATTORNEYS Harold Abergsfrrom Feb. 16, 1943. H. A. BERG STROM 2,311,309

METHOD AND APPARATUS FOR TREATING FIB ROUS CONTAINERS Filed Oct. 22, 1940 3 Sheets-Shani Zla 25a. 26a 2|o.

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. INVENTOR Harold A,Ber'gs1'rom BQMWWIM ATTORNEYS Z"""e.tented Feb. 16, 1943 METHOD AND APPARATUS FOR TREATING .FIBROUS CONTAINERS Iia'roid A. Bergstrom, Van Wert, Ohio, assignor to The Container Company, Van Wert, Ohio, a corporation of Ohio 1 Application October 22,

12 Claims.

My invention relates to a method and appsratus for treating fibrous containers. It has to do, more particularly, with a method and apparatus for drying, baking, or freeing from solvent odors, coating materials applied to containers made of fiber board or other fibrous materials.

In the application of various coating materials to either the inside or outside of fibrous containers, it is sometimes necessary to bake the coatin at such a high temperature that if the entire container was subjected to such a temperature in a conventional oven, the material of the container would become charred, warped, or otherwise damaged. Likewise, certain coating materials applied to such containers must be given a high temperature baking treatment in order to free them of solvent odors.

One of theobjects of my invention is to .provide a method and apparatus for treating fibrous containers of such a nature that either the inside or outside coating applied thereto may be subjected to a high temperature without excessive heating of'the material of which the container is made.

Another object of my invention is to provide a method and apparatus of the type indicated which is of such a nature that the inside or outside coating on the container-may be subjected to a temperature above that which the material of the container could stand without becoming charred, warped, or otherwise damaged.

Another object of my invention is to provide a simple method and apparatus for accomplishing the results indicated above in a very efllcient andeconomical manner. I

According to my invention, the coating applied either to the inside or outside of the fibrous container is subjected to a flash" heating operation to bake, dry, or free it from solvent odors. This is accomplished, according'to the preferred embodiment of my invention, by means of an apparatus which subjects either the inside or the outside of the container to currents 01 very hot air or other gaseous medium. However, the inside or the outside otithe container is subjected to this hot air for ashort period only which is sufllcient todry or bake the coating but which is insuffl'cient to cause penetration of the heat into the material of the container and cause injury thereto.

Y The preferred embodiment of my invention is illustrated in the accompanying drawings wherein similar characters of reference designate corresponding parts and wherein:

1940, Serial No. 362,801"- .1. 34-21) I 4 4 taken through apparatus constructedaccording 'to my invention for heating the interior coating applied to fibrous containers.

Figure 2 is a plan view of the structure shown in Figure 1.

Figure 3 is a transverse vertical sectional view taken substantially along line 3-3 of Figure 1.

Figure 4 is a view similar to Figure 1 but showing an apparatus for heating the exterior coating applied to fibrous containers.

Figure 5 is a transverse vertical sectional view taken substantially along line 5-5 of Figure 4. Figure 6 is a horizontal sectional view taken substantially along line '4 of Figure 5.

With reference to the drawings, and particu-.

iarly to Figures 1 to. 3 inclusive, I have illustrated an apparatus for baking interior coatings to flash" heating "according to my invention." This apparatus comprises woven or heating chamber i whichhas walls of suitable refrac-.

tory or heat insulating material. This oven can be either directly or indirectly fired or heated, with gas, steam, electric heating. units, or any other source of heat energy. For illustrative purposes, I have shown a gas burner 2 in the lower part of the oven.

Aducti isdisposedintheiowerpartofthe oven I and outwardly through an end wall thereof. This duct 3 is preferably connected to the inlet side of a fan 4 disposed outside the oven. The outlet or .pressure side of the fan 4 has a duct 8 connected thereto which leads into a lower portion of the oven at a point beneath the duct 3 and communicates with the interior of the oven. The duct 8 is provided with vertically disposed branches 6 and I which are spaced from each other and which extend upwardly through large openings 8 and Q formed-in the upper wall of the oven. Surrounding the opening 8 is a ring II) which has a seat H for receiving the end of the container and centering it over the opening 8. Similarly surrounding the opening 9 is a ring it which has a seat 13 for receiving the endof the container. The rings ll and I! are removably bolted in place and may be replaced with rings of diflerent sizes degengeigg upon the diameter of the container being Surrounding the branch 6 of the duct 3 in the so oven is a collar H which is adapted to be moved Figure 1 is a longitudinal vertical sectional view 65 vertically on the branch 6. In its uppermost position, this collar I4 is adapted to contact with the inner surface of the upper wall of the oven and to close the annular space in the opening I around the branch 6. Within the branch 6 is a damper 15 which is keyed to a pivot .pin IS. The damper l5 and the collar I4 are adapted to be moved simultaneously. When member I4 is in its lowermost position, the damper I5 is open. When member [4 is moved to its upper position to close the opening 8, the damper I5 is closed. For causing the members I4 and L5 to operate together they are connected together by suitable linkage. Thus, a lever 11 has one end keyed to the end of pivot H5 or the damper. The other end oi this lever is pivoted at l8 to the lower end of a link 19 which has its upper end pivoted to member l4, as at 20. Thus, when member 14 is moved upwardly, the lever II will be swung upwardly and will close damper l6. Associated with the branch duct 1 is an identical arrangement oi members l4 and I5 and their-"connecting parts.

It is desirable in using this apparatus to alternately place over the upper end or branch ducts 6 and I a container to be heated. In Figure 1 the container is shown in inverted position over the branch 6 while the container has been removed irom the branch 1. It is desirable to have the damper l open and the member l4 in'its lowermost position when a container is positioned over the branch duct with whichthese members are associated. Furthermore, it is desirable to have the damper I5 closed and the member l4 in its uppermost position when a container has been removed from the branch duct with which these members are associated. Therefore, I provide a pair of levers 2| which are keyed midway between their ends to a shaft 22. This shaft 22 is rotatably mounted in supports 23 disposed on the top -wall 01 the oven. The shaft 22 may be rotated ,by means 01 a handle 24 keyed to one end there. of. Each end of each lever 2| is connected pivotally a at 25 to the upper end of a rod 26. This rod 26 has its lower, end fastened to one of the members I4, as at 21. Thus, it will be apparent that when the handle 24 is swung in one direction, the member I 4 of one unit will be raised and the damper l5 0! such unit will be closedwhile the member l4 of the other unit will be lowered and the damper l5 oi such unit will be opened.

In the operation of this oven, a container C is positioned on one of the branch ducts, for example duct 6 as indicated in Figure 1. The fan 4 will be in operation and will force air through the oven and upwardly through the opening 8.

- During its passage through the oven, the air will be heated to that high temperature necessary to the other side is kept relatively cool, being exposed to the atmosphere. J Since high temperature air or gas-is used, the lengthpf treatment can be shortened so that the heat will not have time enough to penetrate into the material of the container to an extent whereby it will char,

warp, orotherwise damage the material. At the same time, the coating film is directly in con tact with the high temperature air or gas and reaches the temperature desired almost instantaneously. In practice, short bakes of 600 1''. have been applied without the material of the container becoming more than warm to the touch 7 and with no apparent damage to the container proper which normally will not stand a temperature over 400 F. For example, synthetic resin coatings may be subjected to a temperature 01' 600 for a period of one to two minutes to dry it and remove the solvents without charring or damaging the fiber board of the container.

In Figures 4, 5 and 6, I have illustrated apparatus for accomplishing similar results for treating the coating on the exterior of a fibrous container. In this instance, the oven la is constructed substantially -as before. .A duct 3a is provided and it has branches in and la vertically disposed. However, these branches have iormedwn their upper ends container-receiving chambers lb and lbwhich have their upper edges spaced from the top wall of the oven to provide the spaces 60 and 1c. The openings 6a and 6a in the top wall of the oven receive removable rings Illa and Ho which are adapted to be'just slightly larger than the containerbeing treated so as to allow downward passage of the container therethrough. The chamber 6b is provided with radial supports Ha on which the lower end of the container will rest while the chamber lb is properly treat the coating on the inside of the container. The hot air or gases will pass upwardly along the side walls of the container and then across the end of the container before being drawn downwardly through the branch 6 into the exhaust duct 3. The branch duct 6 should extend up into the container almost to the closed end thereof so that the entire inner surface of the container will be subjected to the hot air and there will be minimum opportunity for dead pockets or eddy currents to develop. The fan 4 will cause the hot gases to quickly circulate through the container. The container need only be positioned on the duct 6 for a. short period to properly treat the coating. During the treatment of the container which is positioned over a branch duct 6, the other containerwill be removed from the branch duct 1 and another will be repositioned thereon. At this time, the member 54 will be in closing relationship to the opening 9 and the damper 15 disposed in branch I will be closed. This will prevent escape and waste of the hot air from the oven and will also provided with similar supports [3a.

tical movement. 'When in its uppermost position, this ring will close the space 60. This ring |4a i 'connected to a damper [5a disposed in duct to by means of linkage Ila substantially like that described in connection with the apparatus shown in Figures 1 to 3. When the ring a is moved to its uppermost position, the damper l5a will be closed and vice versa. The damper 15a and ring 14a of the other unit are identical with those just described.

When the ring 14a of one of theunits is in its lowermost position and the damper l5a'is open, it is desirable that the ring [4a of the other unit be in its uppermost position and the damper I511 of such unit be closed. For this purpose I provide levers 2la which have their opposite endsconnected to the two members Ha by rod 26a. By means of handle 24a, one of the members [4a will be raised while the other is lowered.

In using this apparatus, a container is dropped through one of the rings Illa, for example, the one to the right of Figure 4, and it will rest in chamber 6b on the supports Ila. The upper end of the container C will still extend within the ring I00. to prevent escape of hot air at this point.

A ring or .collar He is mounted on the chamber 6b for ver- 2,s11,soo 3 The hot air will be forced upwardly through the oven and then will be drawn downwardly through space Go, through chamber 61; in contact with the side walls of the container and then underneath the container and on downwardly through the duct So. When the container has been heated for a suflicient time, it may be removed by a suitable expanding tool which may be inserted therein. At the time this one container is being treated, the ring of the other unit a will close the space 1c and the damper I50 of the other unit will be closed. Thus, the hot air will be prevented from escaping from the oven and the atmospheric air will not be drawn in through the branch duct 1a. During treatment of this container, 9. container previouslyin the chamber lb may be removed and a different one to be treated positioned therein.

Thus, with this arrangement, the exterior coating on a fibrous container may be subjected to a "flash heating operation. The interior surface of the container will be in contact with the atmosphere. Thus, overheating will be precluded.

It will be apparent from the above description that I have provided a method and apparatus having many advantages. A number of important advantages have been discussed and others will be readily apparent. v

- Having thus. described my invention, what I claim is:

1. The method of treating a hollow container made of fiber board having a coating substance applied to one surface of the wall thereof which comprises subjecting the coated surface for a period of from one to two minutes to a temperafor the container adaptcd to position the contalner with its inner surface disposed in contact with the atmosphere, said circulating means being of such a nature that the hot gases will be circulated in contact with the exterior surface of the container.

7. Apparatus for treating fibrous containers having a coating substance applied to the exterior thereof comprising a heating oven, multiple openings formed in the upper wall of said oven, multiple container-receiving chambers in communication with said openings, means for supporting containers within said chambers, means for circulating hot gases from said oven through said chambers in contact with the exterior surfaces of said containers, and control means for interrupting the circulation through any one of said chambers while simultaneously producing circulation through other of said chambers. I

8. Apparatus for treating hollow fibrous containers having a coating substance applied to the interior surface thereof comprising a heating oven, a plurality of container treating units assothe edge of the opening to form an outlet through which hot'gases may pass from said oven into the container, an exhaust passage connected to tures of from 400 to 600 F. while simultaneously subjecting the other surface of the wall of the container to a. relatively cool medium to prevent injury to the wall of the container.

2. The method of treating a hollow-container made of fiber board having a coating substance applied to one surface of the wall thereof which the conduit, a blower connected to said exhaust passage, an inlet passage connected to said blower and in communication with said oven to exhaust gases from said exhaust passage and force them into the oven, said conduit having a valve associated therewith for controlling flow of exhaust gases therethrough and said outlet having a valve associated therewith for controlling flow of the comprises circulatingin contact with said surface for a period of approximately one minute hot gases maintained at a temperature of substantially 600 F. while simultaneously subjecting the other surface of the wall of the container to a relatively cool medium to prevent injury to the wall of the container. 4

3. The method of treating a hollow container made of fiber board having a coating substance applied to the inner surface of the wall thereof which comprises circulating in contact with said inner surface for a period of from one to two minutes hot gases maintained at a temperature of from 400 to 600 F. while simultaneously subjecting the outer surface of the wall of the container to a relatively cool medium to prevent injury to the wall of the container.

4. The method of treating a hollow container made of fiber board having a coating substance applied to the outer surface of the wall thereof which comprises circulating in contact with said outer surface for a period of from one to two minutes hot gases maintained at a temperature of from 400 to 600 F. while simultaneously subjecting the inner surface of the wall of the container to a'relatively cool medium to prevent injury to the wall of the container.

5. A method according to claim 2 wherein the said other surface is exposed to the atmosphere.

6. Apparatus for treating a fibrous container havin a coating substance applied to the exterior wall thereof, comprising a heating ov'en, means for circulating hot gases in said oven, a support gases therethrough, means for simultaneously closing and opening said valves, and control means for synchronizing operation of said, last-named meansof the various units so that when thevalves of one of said units are closed the valves of an- I other unit are open. l

9. Apparatus for, treating hollow fibrous containers having a coating substance applied to the interior surface thereof comprising a heating oven having an opening formed in a wall thereof, a conduit projecting through said opening and over which a container is adapted to be slipped with its bottom spaced from the outer end thereof and with its open end surrounding said opening, said conduit being disposed in spaced relationship to the edge of the opening to form an outlet through which hot gases may pass from said oven into the container, an exhaust passage connected to and conduit, a blower connected to said exhaust pastainers having a coating substance applied to the exterior surface thereof comprising a heating oven, a plurality of container-treating units associated with said oven, each of said units including an opening formed in a wall of said oven through which a container may be passed, a containerreceiving chamber disposed within said oven, said container-receiving chamber being in line with said opening and having supporting means associatedtherewith for supporting the container in such a manner that its bottom is spaced from the inner end of the chamber, its open end extends within said opening and its side wall is spaced from the side wall of the chamber, the outer end of said chamber being provided with an inlet for permitting heated gases from said oven to flow into said chamber, a conduit connected to the innor end of said chamber, an exhaust passage connected to the conduit, a blower connected to said exhaust passage, an inlet passage connected to said blower and in communication with said oven to exhaust gases from said exhaust passage and force them into the oven, said conduit having a valve associated therewith for controlling new of exhaust gases therethrough and said chamber inlet having a valve associated therewith for controlling the fiow of gases therethrough, means for simultaneously closing and opening said valves, and control means for synchronizing operation of said last-named means or the various units so that when the valves in one of said units are closed the valves in another unit are open.

11. Apparatus for treating hollow fibrous containers having a coating substance applied to the exterior surface thereof comprising a heating oven having an opening formed in a wall thereof through which a container may beipassed, a container-receiving chamber disposed within said oven, said container-receiving chamber being in line with said opening and having an inlet from the" oven adjacent its outer end, a supporting means associated with said chamber for supporting the container in such a manner that its botconduit, a blower connected to said exhaust passage, an inlet passage connected to said blower and in communication with said oven to exhaust gases from said exhaust passage and force them into the oven, said conduit having a valve associated therewith for controlling flow of exhaust gases therethrough and said chamber inlet having a valve associated therewith for controlling the flow'of gases therethrough, and means for slmultaneously closing and opening said valves.

12. Apparatus for treating hollow fibrous containers having a coating substance applied to one surface of the wall thereof comprising a heating oven having an opening formed in a wall thereof, meansfor supporting a container in association with said opening with its open end in communication with said opening, a conduit associated with said container for cooperating therewith to produce a passageway through which heated gases from the oven will pass for contacting with said coating substance, said passageway having an inlet connected-to the oven and having an outlet,

an exhaust conduit connected to said outlet, 11

blower connected to said exhaust conduit, an inlet passage into the oven connected to said blower to exhaust gases from said exhaust conduit and force them into the oven, a valve associated with said passageway for controlling flow of exhaust gases therethrough, a valve for controlling the inlet to said passageway, and means for opening and closing both or said valves simultaneously.

HAROLD A. BERGS'IROM. I 

